Press operating valve with rapid advance and full pressure positions



Aug. 1, 1950 INVENTOR Y ROBERT K. SEDGWIGK B VANCE AND ITIONS POS l8Filed March FULL PRESSURE mm: mm 4 5 we: 2 E

amhnmz R. K. SEDGWICK PRESS OPERATING VALVE WITH RAPID AD Mum m 8 mmATTORNEY Patented Aug. 1, 1950 UNITED STATES PATENT OFFICE PRESSOPERATING VALVE WITH RAPID AD- VANCE AN D FULL PRESSURE POSITION S.

Robert K. Sedgwick, Oak Park, Ill., assignor to American SteelFoundries, Chicago, 111., a corporation of New Jersey Application March1a, 1948, Serial No. 15,534

7 Claims.

chamber 12 receiving a pipeor tube !4 carried by the casting 2 andslidably fitted in the ram at [6 in substantially fluid-tight engagementthere with. Supported by the casting is a tank or reservoir [8 adaptedto contain low pressure fluid communicating with the chamber 8 on therapid adit is frequently desirable to incorporate what is known in theart as a speed change control to slow the advance stroke of thehydraulic motor before the resistance of the work is encountered and tothereafter initiate the full pressure stroke of the motor against thework. In prior art arrangements, many control mechanisms have beenintroduced for this purpose and usually involve multiplicity of valvesand complicated piping arrangements.

Accordingly, it is a primary object of the present invention to device asingle operating valve capable of controlling the rapid advance andpullback strokes of the motor and also capable of effecting speed changecontrol for the purpose above described.

A further object of the invention is to devise a valve, such as abovedescribed, incorporating novel means for throttling the discharge ofhydraulic fluid from the prefill valve of the hydraulic motor as thepullback phase of the motors cycle is initiated. By this means, suddenopening of the prcfill valve means and consequent noise and damage tothe equipment is prevented.

The foregoing and other objects and advantages of the invention willbecome apparent from a consideration of the following specification andthe accompanying drawing, wherein:

Figure 1 is a diagrammatic view of an hydraulic press incorporating thenovel circuit, portions of the structure being broken away in verticalcross section to clarify the illustration;

Figure 2 is an enlarged vertical cross sectional view taken on thelongitudinal axis of the operating valve with the stem thereof shown inelevation; and

Figure 3 is a cross sectional view taken on the line 3-3 of Figure 2.

Describing the invention in detail and referring first to Figure 1, thepress comprises a cylinder casting 2 and a ram 4 having a head 5defining a main advance chamber 8 and a return or pullback chambcr [0Within the casting. I The ram 4 is hollow and comprises an internalrapid advance Vance stroke and the pullback stroke of the ram and cutoff from communication with the main advance chamber 8 on the iullpressure stroke of the ram by aprefill valve Zllincluding a casin 22with ports 23 connected to the reservoir. The

casing contains a stem 24 spring-pressed to its,

open position by a spring 28 reacting against the casing 22 and a springseat 30 connected to the stem.

h ycle of the press is controlled by a single operating valve, generallydesignated 352, and shown in detail in Figures 2 and 3, wherein it willbe seen that the valve comprisesa body or casing 34 havin a longitudinalhere or passage 36 contaming a hollow s em 38 havin four 511001 or lands2, 4 nd 46 and lso having a longitudinal passage 48 connected to thebore 36 y ports 50, 52, 54 and 56 through the respective lands of thestem,

The body 34 comprises an annular prefill chamber 58, a prefill exhaustor throttle chamber 60, a air of main exhaust ehambers E2 and $4, arapid advance chamber 66, an inlet or. hi h pressure delivery chamber 58and a pullback chamber 10. 1

The prefill exhaust chamber 5'! isconnccted directly to the tank by aport 12, as best scenin Figure and he exhaust chambers 62 nd 64 asimilarly connected to the tank by ports (not shown). The nds of thebore 36 are connected to the tanks by ports 13.

The inlet chamber 68 is connected by a port 14 (Figure 2) to a pump 16.(Fi ure 1) operated by a motor 18, the suction side oithe ump beingconnected by a line to the tank It. V

The prefill chamber 58 is connected by a line 82 to the top of thecasing 22 above the stem 24 and is connected through aconventionalspring pressed check valve 4 to the main chamber 8 of thehydraulic motor.

The r pid advance chamber 66 of the valve 32 is connected by a line 88to the tube It and the pullback chamb r 0 of the valve is onne d y aline so to the pullback chamber ill of the bio draulic motor.

As indicated in Figure 1, the valve 32 is prefer.- ably actuated bypneumatic motors 921 and 94;; however, the valve m y be a uated ma ua orin any other desiredmanner, T e motor, 92

in Figure 2, the pressure fluid from the pump 16 is delivered to theinlet chamber 88 and flows through the port 54 and the passage 48 intothe ports 52 and 5G and thence to exhaust through the chambers 62 and54. Under these conditions, the prefill valve casing 22 is exhaustedthrough the line 82, the prefill valve chamber 58 and the prefillexhaust valve chamber 66 inasmuch as the spool or land 40 of the stem38, as best seen in Figure 2, accommodates flow of fluid from thechamber 58 to the chamber (iii.

The stem 38 is actuated to rapid advance position, indicated at theright extremity of Figure 2, by the motor 92 and, in this position ofthe stem, fluid is delivered from the inlet chamber '68 to the rapidadvance chamber 66 and the pullback chamber It is exhausted through theexhaust chamber 64. Under these conditions the prefill valve chamber 58is closed by the prefill land or spool 40.

In the full pressure stroke of the stem 33, indicated at the right ofFigure 2, fluid from the inlet chamber 68 is delivered. to the rapidadvance chamber 66 and thence into the ports 52 which, under theseconditions, overlap the chamber 66. The fluid flowing into the ports 52is conveyed through the passage 48 and the ports 50 into the prefillvalve chamber .58 inasmuch as the ports 50, under these conditions, aredisposed within the latter chamber. Thus fluid is conveyed to the line82 (Figure 1) into the casing 22 acting upon the top area of the preflllvalve stem 24 to urge the latter to its closed position. The fluid thenflows through the check valve 84 which is adapted to create a slightback pros sure to close the stem 24 before delivery of fluid through theline 82 to the main advance chamber 8. Under these conditions, pressureis developed against the full cross sectional area of the head 6 on thefull pressure stroke of the-ram 4. It may be noted in this connectionthat closing of the prefill valve stem 24 checks the rapid advancestroke of the ram 4 prior to initiation 4 of the pullback stroke, thestem is actuated by the motor 94 to the neutral position shown in Figure2 preparatory to initiation of a new cycle.

It will be understood that the valve 32 may be actuated by manuallyoperated means or may be automatically actuated by any suitable positionor pressure responsive means, such" as are well known in the art. t willbe understood that I do not wish to be limited by the exact embodimentof the device shown which is merely by way of illustration and notlimitation as various and other forms of the device will, of course, beapparent to those skilled in the art without departing from the spiritof the invention or the scope of the claims.

I claim:

1. In an hydraulic actuating circuit for an hydraulic motor having mainadvance and pullback chambers, ram means presenting main. advance andpullback areas in respective chambers and presenting a rapid advancearea spaced from, the first-mentioned areas, a reservoir. of low.

pressure hydraulic fluid, and prefill valve meansadapted in theopenposition thereof to'connect communication between said reservoir andsaid,

main advance chamber, said prefill valve means,

i comprising a closing pressure area adapted. when of the full pressurestroke thereof against the work. I

In the pullback or reverse position of the stem 38, as indicated at theright of Figure 2, pressure fluid is delivered from the inlet chamber 68to the pullback'chamber I0 and is exhausted from the rapid advancechamberiifi to the exhaust chamber 62. At the same time, the prefillvalve chamber 58 is exhausted at a predetermined rate through the port12. This rate is determined by a throttle screw 95 threaded into thebody 34 and held in adjusted position in the port 12 by alock nut 98.The outer end of the screw is provided with a cap nut I00 protecting asquare extremity "12 of the screw adapted for actuation by a suitabletool, such as a wrench.

Thus due to the throttlingof fluid exhausted through the port 12, theprefill valve gradually opens at an adjustable predetermined ratepreventing shock to the tank as the ram is actuated on the return orpullback stroke thereof by delivery of pressure fluid fromthe valvepullback chamber 10 through the line 90 to the pullback chamber In ofthe hydraulicmotor. At the end acted upon by pressure fluid to closesaid prefill valve means: .the combination, of an operating: valveincluding a body with an internal bore having a prefill chamber,a-preflllexhaust cham -a chamber, a pressure inlet chamber, a pullbackchamber, and another main exhaust chamber. spaced in the foregoingsequence along said bore,

said exhaust chambersbeing connected to saidreservoir, said prefillchamber being connected to:

a port of said prefill valve means containing the closing area thereofand also being connected to.

saidmainadvance chamber through onewa vcheck valve means foraccommodating flowmof fluid. to themain advance chamber after apredetermined back pressure has-been built up against said prefill valvearea, a connection be tween the rapid advance chamber and the rapidadvance area, and a connection between. said,

pullback chambers, a stem comprising a plurality of lands slidablyfitted in said bore, said stern. being so formed and arranged that inthe neutral position thereof one of said lands accommodates flow offluid from the prefill chamber to the pre fill exhaust chamber, theother exhaust :cham bers and the inlet chamber being covered by theother lands respectively,passage means through said stem extendingthrough all of said. lands and adapted in the neutral, position of thestem tooonnect the inlet chamber to the main exhaust chambers, said stembeing adapted inthe rapidadvance position thereof to close the prefill.chamber, to direct flow of fluid from the inlet chamber to the rapidadvance chamber and to exhaust flow of fluid from the pullback chamberto said, other main exhaust chamber, said stem being adapted in the fullpressure position thereof to direct flow of. fluid from the inletchamber to the rapid advance chamber, to direct fluid from the rapidadvance chamber through said passage means to the prefillchamber and toexhaust the pullback chamber. to said other main exhaust chamber, andsaid stem. being. adapted in the reverse position thereof to direct flowof fluid from the inlet chamber tothe pull back"chamber, toexhaiis't"the "rapid advises chamber to said one main exhaust chamber and toexhaust the prefill chamber to the prefill exhaust chamber, and a sourceof high pressur fluid connected to the inlet chamber.

2. A circuit, according to claim 1, wherein said body is provided withmeans for adjustably throttling flow of fluid from the prefill exhaustchamber tothe reservoirs i "3. An operating valve for deliveringpressure fluid comprising a body withan internal bore having a prefillchamber, a prefill exhaust chamber, a main exhaust chamber, a rapidadvance chamber, a pressure inlet chamber, a pullback chamher, andanother main exhaust chamber spaced in the foregoing sequence along saidbore, a stem comprising a prefill land, aninlet land,'and a pair ofexhaust lands slidably fitted insaid bore, said stem being so formed andarranged that in the neutral position thereof said prefilllandaccommodates flow of fluidfrom the" prefill chamber to the prefillexhaust chamber, the'other exhaust chambers and the inlet chamber beingcovered by the exhaust lands and the inlet land respectively, passagemeans through said stem having ports extending throughrespective landsand otherwise spaced fromsaid bore, said passage means being adapted inthe neutral position of said stem to connect the inlet chamber to themain exhaust chambers, saidstembeing so formed and arranged that in therapid advance position thereof said prefill land closes said prefillchamber positively preventing flow of fluid therethrough while the inletland and one exhaust land accommodate flow of fluid fromthe inletchamber to the rapid advance chamber and the other exhaust landaccommodates flow of fluid from the pullback chamber to the exhaustchamber, said stem being so formed and arranged that in the fullpressure position thereof the ports in said one exhaust land overlap therapid advance chamber and the ports in the prefill land communicate withthe prefill chamber, said one exhaust land accommodating flow of fluidfrom the inlet chamber to the rapid advance chamber and said otherexhaust land accommodating flow of fluid from the pullback chamber tosaid other exhaust chamber, and said stem being so formed and arrangedthat in the reverse position thereof the inlet land and said otherexhaust land accommodate flow of fluid from the inlet chamber to thepullback chamber and said one exhaust land accommodates fiow of fluidfrom the rapid advance chamber to the first-mentioned exhaust chamberand the prefill land accommodates flow of fluid from the prefill chamberto the prefill exhaust chamber.

4. A valve, according to claim 3, wherein said body is provided withmeans for adjustably throttling flow of fluid from the prefill exhaustchamber.

5. A valve comprising a body with an internal bore having sevenchambers, a stem in said bore having four lands slidably fitted withinthe bore, the stem being so formed and arranged that in the neutralposition thereof the first land accommodates fiow of fluid between thefirst and second chambers while the second, third and fourth lands coverthe third, fifth and seventh chambers respectively, a passage throughsaid stem having ports connected to each land, the ports in the second,third and fourth lands being disposed within chambers covered thereby inthe neutral position of the stem while the ports in the first land arespaced from the first chamber, said stem being so formed and arrangedthat in a first advance position thereof the third land accommodatesfiow'of fluid between the fourth and fifth chambers and the fourth landaccommodates flow of fluid between the sixth and seventh chambers andthe second land accommodates flow of, fluid between the second and thirdchambers, the first chamber being blocked by the first land and allports being blocked by engagement with the bore, said stem being soformed and arranged that in a second advance position thereof the portsin the first land are disposed within the first chamber and the, portsin the second land overlap the fourth chamber to accommodate flow offluid between the fourth and fifth chambers andthrough the passage tothe first chamber, the fourth land accommodating flow of fluid betweenthe sixth and seventh chambers, and said stem being soformed andarranged that in a reverse position thereof the first and second landsaccommodate flow of fluid between the first and second chambers, thesecond and third lands accommodate flow of fluid between the third andfourth chambers and the third and fourth lands accommodate flow of fluidbetween the fifth and sixth chambers, all of the ports being blocked byengagementwith the bore, a port connected to each chamber, and means foradjustably throttling flow of fluid through the port of the secondchamber. a i i i l 6. A. valve comprising a body with an internal borehavingseven chambers, a stem in said bore having four landsslidablyifitted within the bore, the stem being so formed and arrangedthat in the neutral position thereof the first land accommodates flow of'fluid betweenthe first and second chambers while the second, third andfourth lands cover the third, fifth and seventh chambers respectively, apassage through said stem having ports connected to each land, the portsin the second, third and fourth lands being disposed within chamberscovered thereby in the neutral position of the stem while the ports inthe first land are spaced from the first chamber, said stem being soformed and arranged that in a first advance position thereof the thirdland accommodates flow of fluid between the fourth and fifth chambersand the fourth land accommodates flow of fluid between the sixth andseventh chambers, the first chamber being blocked by the first land andall ports being blocked by engagement with the bore, said stem being soformed and arranged that in a second advance position thereof the portsin the first land are disposed within the first chamber and the ports inthe second land overlap the fourth chamber to accommodate flow of fluidbetween the fourth and fifth chambers and through the passage to thefirst chamber, the fourth land accommodating flow of fluid between thesixth and seventh chambers, and said stem being so formed and arrangedthat in the reverse position thereof the first and second landsaccommodate flow of fluid between the first and second chambers, thesecond and third lands accommodate flow of fluid between the third andfourth chambers and the third and fourth lands accommodate fiow of fluidbetween the fifth and sixth chambers, all of the ports being blocked byengagement with the bore,

7. In an hydraulic actuating circuit for an hydraulic motor having mainadvance and pullback chambers, ram means presenting main advance andpullback areas in respective chambers and presenting a rapid advancearea spaced from the first-mentioned areas, a reservoir of low pressurehydraulic fluid, and prefill valve means 7 adapted in the open positionthereof to connect said reservoir and said main advance chamber andadapted in the closed position to cut off communication between saidreservoir and said main advance chamber, said prefill valve meanscomprising a closing pressure area adapted when acted upon by pressurefluid to close said prefill valve means; the combination of an operatingvalve including a body with an internal bore having a prefill chamber, aprefill exhaust chamber, a main exhaust chamber, a rapid advancechamber, a pressure inlet chamber, a pullback chamber, and another mainexhaust chamber spaced in the foregoing sequence along said bore, saidexhaust chambers being connected to said reservoir, said prefill chamberbeing connected to a port of said prefill valve means containing theclosing area thereof and also being connected to said main advancechamber through one-way check valve means for accommodating flow offluid to the main advance chamber after a predetermined back pressurehas been built up against said prefill valve area, a connection betweenthe rapid advance chamber and the rapid advance area, and a connectionbetween said pullback chambers, a stem comprising a plurality of landsslidably fitted. in said bore, said stem being so formed and arrangedthat in the neutral position thereof one of said lands accommodates flowof fluid from the prefill chamber to the prefill exhaust chamber, theother exhaust chambers and the inlet chamber being covered by the otherlands respectively, passage means through said stein extending throughall of said lands and adapted in the neutral position of the stem to 8.connect the inlet chamber to the main exhaust chambers, said stem beingadapted in the rapid advance position thereof to close the preflllchamber, to direct flow of fluid from the inlet chamber to the rapidadvance chamber and to exhaust flow of fluid from the pullback chamberto said other main exhaust chamber, said stem being adapted in the fullpressure position thereof to direct flow of fluid from the inlet chamberto the rapid advance chamber, to direct fluid from the rapid advancechamber through said passage means to the prefill chamber and to exhaustthe pullback chamber to said other main exhaust chamber, and said stembeing adapted in the reverse position thereof to direct flow of fluidfrom the inlet chamber to the pullback chamber, to exhaust the rapidadvance chamber to said one main exhaust chamber and to exhaust theprefill chamber to the prefill exhaust chamber, and a source of highpressure fluid connected to the inlet chamber, the ends of said borehaving ports connected to said reservoir.

ROBERT K. SEDGWICK.

REFERENCES CITED The following references are of record in th file ofthis patent:

UNITED STATES PATENTS Number I Name Date 226,218 Wilson Apr. 6, 18801,780,471 Galloway et a1. Nov. 4, 1930 2,004,399 Svenson June 11, 19352,048,789 Fiegel et a1 July 28, 1936

